1. Field of the Invention
The invention relates generally to a product authentication system and method and, more particularly, a product authentication system and method in which an authentication or security mark comprising a code that is not visible under visible light is applied on a label.
2. Description of the Related Art
Various techniques have been used to identify articles in an effort to reduce counterfeiting. For collectibles such as art works and sports memorabilia, where a single item may be worth millions of dollars, a technique that is highly refined and virtually impossible to copy is desired. This is because high potential counterfeiting gains will motivate counterfeiters to invest large sums of money and resources to defeat the anti-counterfeit measure. Similarly, the high cost of implementing an anticounterfeit measure for collectibles is typically accepted by the owner or insurer, because the potential loss from counterfeiting is great.
On the other hand, for mass produced items such as apparel, CDs, and audio and video cassettes, cost is a more important factor in implementing an anti-counterfeit measure. The implementation cost must be small enough so that the cost of the protected product will not increase dramatically. Yet, the anti-counterfeit measure must be refined enough so that counterfeiters will be unable to defeat the anti-counterfeit measure in a sufficiently easy manner such that they will be able to economically produce and sell counterfeit goods.
Mass produced items also have to be protected against product diversion. Product diversion occurs when a counterfeiter acquires genuine, non-counterfeit goods that are targeted for one market and sells them in a different market. The counterfeiter does this to circumvent the manufacturer's goal of controlling the supply of his or her goods in a particular market and, as a consequence, benefits from the sales in that limited supply market or in the diverted sales market.
In one type of anti-counterfeit and anti-diversion measure, an ultraviolet (UV) ink is used to mark the product with an identifying indicia. One benefit of using the UV ink is that it is typically not visible when illuminated with light in the visible spectrum (380-770 nm), but is visible when illuminated with light in the UV spectrum (200-380 nm). Therefore, counterfeiters will be unable to tell whether the product contains a security mark by merely looking at the product when the product is illuminated with visible light.
A number of UV inks are readily available in the security industry and can be obtained at a relatively low cost. Several UV ink types and compositions are described, for example, in U.S. Pat. No. 5,569,317, entitled "Fluorescent and Phosphorescent Tagged Ink for Indicia" the disclosure of which is incorporated by reference herein. This patent discloses a security mark that becomes visible when illuminated with UV light having a wavelength of 254 nm.
However, the use of security marks containing a UV ink has seen increased use and counterfeiters have become knowledgeable about their use. It has been a common practice for counterfeiters to examine the UV ink from a product sample, reproduce or procure the same or similar UV ink that matches the characteristics of the UV ink from the product sample, and apply the same security mark on the counterfeit products using the substitute UV ink.
In another type of anti-counterfeit and anti-diversion measure, an infrared (IR) ink is used to mark the product with an identifying indicia. As with the UV ink, one benefit of using the IR ink is that it is typically not visible when illuminated with light in the visible spectrum, but is visible when illuminated with light in the IR spectrum (800-1600 nm). An additional benefit of using the IR ink is that it is more difficult to reproduce or procure the matching IR ink by studying a product sample containing the IR security mark. Examples of IR security mark usage are given in U.S. Pat. Nos. 5,611,958 and 5,766,324. The disclosures of these patents are incorporated by reference herein.
Widespread use of IR security marks have been limited, however, because of cost. Up-converting phosphors that are contained in IR inks are generally more expensive and less readily available than down-converting phosphors that are contained in many UV inks.
Biologic security marks have also been used to combat counterfeiting and product diversion, but their use have also been limited due to cost.
Combination security marks have also been proposed. In U.S. Pat. Nos. 5,360,628 and 5,360,628, the disclosures of both of which are incorporated by reference herein, a security mark comprising a visible component and an invisible component made up of a combination of a UV dye and a biologic marker, or a combination of an IR dye and a biologic marker is proposed. Also, in U.S. Pat. No. 5,698,397, the disclosure of which is incorporated by reference herein, a security mark containing two different types of up-converting phosphors is proposed.